The following account of the prior art relates to one of the areas of application of the present application, hearing aids.
Traditionally, ‘spatial’ or ‘directional’ noise reduction systems in hearing aids operate using the underlying assumption that the sound source of interest (the target) is located straight ahead of the hearing aid user. A beamforming system is then used which aims at enhancing the signal source from the front while suppressing signals from any other direction.
In several typical acoustic situations, the assumption of the target being in front is far from valid, e.g., car cabin situations, dinner parties where a conversation is conducted with the person sitting next to you, etc. So: in many noisy situations, the need arises for being able to “listen to the side” while still suppressing the ambient noise.
EP2701145A1 deals with improving signal quality of a target speech signal in a noisy environment, in particular to estimation of the spectral inter-microphone correlation matrix of noise embedded in a multichannel audio signal obtained from multiple microphones present in an acoustical environment comprising one or more target sound sources and a number of undesired noise sources.